abc-notation-transposition/tests/unit/classes/simple-circular-array.test.js

A robust utility for transposing ABC Notation by half steps.

const {SimpleCircularArray} = require('../../../classes/SimpleCircularArray');

test('size method of SimpleCircularArray should return the correct size', () => {
    const array1 = new SimpleCircularArray();
    const array2 = new SimpleCircularArray([0,1,2,3]);
    expect(array1.size()).toBe(0);
    expect(array2.size()).toBe(4);
})
 
test('get method of empty SimpleCircularArray should throw error', () => {
    const array = new SimpleCircularArray();
    expect(() => array.get(1)).toThrow(new Error("Cannot access element of array length 0."));
});

test('findIndex method of empty SimpleCircularArray should return -1', () => {
    const array = new SimpleCircularArray();
    expect(array.findIndex(() => true)).toBe(-1);
});

test('find method of empty SimpleCircularArray should return undefined', () => {
    const array = new SimpleCircularArray();
    expect(array.find(() => true)).toBe(undefined);
})

test('get method of SimpleCircularArray length 1 should behave in circular manner with positive indices', () => {
    const array = new SimpleCircularArray([0]);
    for(let i = 0; i <= 30; i++) {
        expect(array.get(i)).toBe(0);
    }
});

test('get method of SimpleCircularArray length 1 should behave in circular manner with negative indices', () => {
    const array = new SimpleCircularArray([0]);
    for(let i = 0; i >= -30; i--) {
        expect(array.get(i)).toBe(0);
    }
});

test('findIndex method of SimpleCircularArray length 1 should return 0 for item that exists', () => {
    const array = new SimpleCircularArray([0]);
    expect(array.findIndex((elem) => elem === 0)).toBe(0);
});

test('findIndex method of SimpleCircularArray length 1 should return -1 for nonexistent item', () => {
    const array = new SimpleCircularArray([0]);
    expect(array.findIndex((elem) => elem !== 0)).toBe(-1);
});

test('get method of SimpleCircularArray length 10 should behave in circular manner with positive indices', () => {
    const array = new SimpleCircularArray([0,1,2,3,4,5,6,7,8,9]);
    let j = 0;
    for(let i = 0; i <= 30; i++) {
        expect(array.get(i)).toBe(array.get(j));
        j++;
        if(j >= array.size()) j = 0;
    }
});

test('get method of SimpleCircularArray length 10 should behave in circular manner with negative indices', () => {
    const array = new SimpleCircularArray([0,1,2,3,4,5,6,7,8,9]);
    let j = array.size() - 1;
    for(let i = -1; i >= -30; i--) {
        expect(array.get(i)).toBe(array.get(j));
        j--;
        if(j < 0) j = array.size() - 1;
    }
});

test('findIndex method of SimpleCircularArray length 10 should return index of existing item', () => {
    const array = new SimpleCircularArray([0,1,2,3,4,5,6,7,8,9]);
    expect(array.findIndex((elem) => elem === 8)).toBe(8);
});

test('findIndex method of SimpleCircularArray length 10 should return -1 for nonexistent item', () => {
    const array = new SimpleCircularArray([0,1,2,3,4,5,6,7,8,9]);
    expect(array.findIndex((elem) => elem === 10)).toBe(-1);
});

test('find method of SimpleCircularArray length 10 should return found item', () => {
    const array = new SimpleCircularArray([0,1,2,3,4,5,6,7,8,9]);
    expect(array.find(elem => elem === 0)).toBe(0);
});

test('find method of SimpleCircularArray length 10 should return undefined for nonexistent item', () => {
    const array = new SimpleCircularArray([0,1,2,3,4,5,6,7,8,9]);
    expect(array.find(elem => elem === -1)).toBe(undefined);
});